Dennis Dutton: A Darwinian Theory of Beauty
24/5/12
Evolución
Robert Sapolsky: Are Humans Just Another Primate?
19/5/12
WOW.
What Remains Unclear
miércoles, 16 de mayo de 2012
What remains unclear
Este viene a ser el cierre del libro de David Christian This Fleeting World, breve historia de la humanidad y su desarrollo:
What remains unclear, then, is whether the modern revolution will lead to the emergence of a new global system capable of relative ecological, economic, and political stability, or whether the accelerating change of the modern era is the prelude to a sudden, sharp collapse that will drive many parts of the world back to the productivity levels of the early agrarian era, if not even further. Perhaps the fundamental paradox of the modern revolution is that on the one hand human control over the biosphere has increased spectacularly: yet, on the other hand we have not yet shown that we can use that control in ways that are equitable and sustainable. Are we really in control of our astonishing creativity as a species? We must wait to see whether the astonishing collective achievements of our species will prove ephemeral or enduring.
Lo cual nos remite, por amenaza ominosa, a la hipótesis de Olduvai, y al posible colapso de la civilización industrial por sobrepeso y crisis energética.
Cuando hablamos de "el hombre", "el ser humano", solemos entender por ello nosotros, el homo sapiens. Pero el Homo sapiens es una especie en expansión acelerada, una especie creativa, que no se adapta a su ecosistema, sino que lo transforma aceleradamente, en una espiral de retroalimentación que también lo transforma a él... a la vez que aumentan sus números hasta ahora incesantemente, con una explotación cada vez más intensa del entorno.
Somos una especie reciente, y rara. Nuestra fase histórica, lo que solíamos llamar la historia, es aún más reciente, y la fase urbana/industrial, apenas un suspiro a nivel histórico. Yo mismo provengo, como muchos, de un pueblo, y he pasado a engordar una ciudad.
Una especie humana anterior, el Homo erectus, tenía una relación más armónica y sostenible con su entorno, mucho más... pero apenas lo consideraríamos humano si lo viésemos, más bien un Yahoo—Swift los describió bien. El Homo erectus desarrolló su cultura sostenible durante dos millones de años, veámoslo en una línea temporal comparada con el tiempo de nuestra propia cultura humana. Cada puntito son diez mil años:
Homo erectus: ....................................................................................................................................................................................
Homo Sapiens
(hasta ahora): ................
Pero de esta existencia, la historia escrita no ocupa sino esto: .
La mayor parte del resto es una historia de cazadores-recolectores, no muy distinta todavía en su ecología de la del Homo erectus. La era de la agricultura y las poblaciones viene a ser así de larga: ..
Esto se ha acelerado, señores. De momento somos la excepción, y yo podría la mano en el fuego por el Homo erectus como especie con una economía sostenible, antes que por nosotros.
Comparen ahora la curva del crecimiento de la población: una horizontal primero, una pendiente creciente durante la era agrícola, y un disparo vertical hacia arriba en la era industrial, que amenaza tender al infinito y juntarse con la asíntota—cosa imposible, claro. Antes de eso, pasa algo... matemáticamente. No lo digo yo.
Este crecimiento acelerado reciente viene causado por la organización creciente, la información, el comercio y el desarrollo técnico... pero también, y muy visiblemente en su fase industrial, por la explotación de combustibles fósiles, carbón primero, petróleo luego, cuando la cosa se dispara realmente. Y ahora, a principios del siglo XXI, hemos pasado el cénit de la explotación del petróleo. Pero no el cénit de la población, en absoluto. Las dos curvas que crecieron durante el siglo XX a la par, población y energía, las dos disparadas hacia arriba, ahora se separan: la población continúa hacia arriba como una flecha, el petróleo se estabiliza y nos crea una crisis, antes de comenzar su descenso ineluctable según predijo M. King Hubbert:
Descuiden, la población también bajará, y puede que nos dé un susto la manera elegida para ello. La era del petróleo dura doscientos años a todo tirar: cien años de curva ascendente, cien años de descendente... si se se cumpliesen estas previsiones digamos optimistas sobre el petróleo que se ha de descubrir todavía.
Hemos vivido ya la era del petróleo en su fase creciente, y ahora nos espera el descenso. Nos quedamos sin futuro previsible, o quizá demasiado previsible, al quedarnos sin petróleo, y con una población disparada en su crecimiento y con un desarrollo insostenible. De ahi viene la deuda insolvente, las expectativas inciertas, la crisis del capital; de ahí vendrán las guerras y los desastres masivos que se producirán ahora, con tanta seguridad como cae una lanza al suelo después de su curva ascendente. Me temo que el futuro que espera a nuestros hijos y nietos va a ser indeseable, si no espantoso, para la mayoría. Nuestra especie ha tenido un éxito fulgurante a costa de quemar todos los cartuchos de golpe, y fundirse la herencia de los descendientes.
Y los últimos hombres, en un futuro aún lejano, quizá sean como los primeros. No nos agradaría verlos.
Purposiveness without a purpose
martes, 15 de mayo de 2012
Purposiveness without a purpose
Religion is the subject (however implicitly stated) of an interesting phrase in Darwin, which stresses the importance of group selection. A group with closely-knit ties, mutual altruism, and a spirit of individual sacrifice for the group would possess a competitive advantage. "Together we stand, divided we fall". Nationalism, too, or patriotism, is a kind of religion in this sense. But, apart from their role as social glue, there must be something to religions which is psychologically advantageous from an evolutionary viewpoint: perhaps that is the sense (the illusion) of an aim or purpose in the thinking individual's life and actions - above all once they have been subordinated to the ideals of the group. I mean a ready-made purpose you can stick to without having to look too much around for it, which may be disorienting and costly from the point of view of energetic efficiency. After all, many thinking individuals can't waste their time thinking about what they should be thinking about.
(A comment on Sacred Fictions, in The Storytelling Animal).
I suppose this reflection (together we stand, divided we fall) may apply at many levels. At the the level of world civilization, in which fanatical nationalisms and religions are a dangerous element of confrontation. And at the level of the individual, who may also be a house divided against himself when the same person is intellectually, socially or emotionally committed to different or even contrary ideological systems.
_____
L'homme ne poursuit que des chimères.
Man follows only phantoms.
The last words of Pierre-Simon de Laplace, according to Augustus De Morgan.
Qué gen buscar
11/5/12
Estaba viendo un programa sobre los neandertales y la secuenciación de su genoma, con el descubrimiento del famoso gen que facilita la producción del lenguaje y que también se encontró en ellos. Este gen, nos explican, también se implantó en ratones, y modificó sustancialmente la manera en que "vocalizaban" sus chillidos, además de producir otros cambios cerebrales. (Shades of Dr. Moreau...). Hablamos algo de estas investigaciones en "Orígenes del Bable", a cuenta de los neandertales asturianos.
Hay que apuntar que un elemento esencial en la lenguaje humano es, aparte de cuestiones de procesamiento de la vocalización, la ideación: la capacidad simbólica de establecer equivalencias entre una representación y otra, entre un significante y un significado. La capacidad de asociar ideas, y luego de tratar esa misma asociación como un objeto unificado que puede asociarse a otra idea. Crucial en esta capacidad es, sin duda, la bien conocida propiedad de las neuronas huamnas para desarrollar activaciones conjuntas, y redes neuronales como producto de la experiencia—el principio, en sustancia, de fire together - wire together, o desarrollo conjunto por activación conjunta. (Más sobre esto en "Training the train of ideas", y en "Redes neuronales y consciencia". Las neuronas espejo son sin duda campo de investigación primordial en el que buscar este tipo de expresión de los genes.
En cuanto al gen específico que se haya de buscar, será el que haya supuesto con su mutación un desarrollo espectacular en la capacidad lingüística, un gran salto adelante, probablemente en los humanos modernos. Esto sería los más próximo al "órgano del lenguaje" de Chomsky aparecido por mutación—hipotéticamente—aunque no conviene exagerar su papel crucial, pues tanto el lenguaje como el simbolismo en general descansan en una serie de comportamientos y prácticas sociales muy anteriores a la aparición del homo sapiens moderno. Ahora bien, puestos a buscar, lo que hay que buscar ha de ser un gen que facilite o potencie el establecimiento de conexiones dendríticas entre neuronas que se activan conjuntamente, o un gen (o grupo de genes) que de alguna manera potencie la comunicación bidireccional entre estas neuronas frecuentemente asociadas. Un activador de las conexiones, en suma, que ayude a explicar la mayor flexibilidad y potencial creativo del lenguaje y el pensamiento humano, frente a las capacidades mucho más estables o estólidas de especies como los neandertales y los homo erectus. Quizá la clave haya de ser precisamente el gen o las modalidades de expresión del mismo que no encontremos en los neandertales, y sí en cambio en los humanos modernos.
Homo Erectus - Battle for Planet Earth
10/5/12
Un documental-ficción de la BBC, sobre el hipotético encuentro, poco amistoso, entre el homo sapiens y el homo erectus hace 74.000 años:
Es un documental excelente, muy atento a las peculiaridades cognitivas del homo sapiens que lo diferenciaban de las anteriores especies humanas. El contexto en que se sitúa es el cuello de botella de población humana creado tras la explosión del volcán Toba, y la difícil supervivencia en un ecosistema degradado. Recuerdan un tanto, las condiciones angustiosas, la competición inhumana y la precariedad de la supervivencia, a la novela y película The Road. Deben seguir los dos guiones unas estrictas estructuras antropológicas de la imaginación.
(Y aquí hay otro capítulo similar, sobre el encuentro con los neandertales).
Consilience Conference
10/5/12
Consilience conference at St Louis (April 2012). Final address by David Sloan Wilson.
Additional audios by E. O. Wilson, Massimo Pigliucci, John Hawks et al. here at the This View of Life website on evolution.
Not from this conference, but closely related, here follows a 2008 lecture by E. O. Wilson at UCSD, on "The Coming Synergism between Science and the Humanities", i.e. "consilience".
The borderland disciplines between science and the humanities, according to Wilson:
- Cognitive neuroscience: mapping brain activity, defining mental development and process.
- Behavioral genetics: identifying the hereditary basis of mental development and process.
- Evolutionary biology: reconstructing the evolutionary history of mental development and process.
- Environmental sciences: describing the physical environment to which humanity is adapted.
And here, a 2008 interview with E. O. Wilson, in conversation with Patricia Churchland:
A Comment on Truth, Science, and Evolution
25/4/12
At ResearchGate—a debate on whether evolutionary theory is scientific or true, and the criteria for scientificity:
I think truth comes in all kinds of fuzzy packets - e.g. what is true for the members of a Muslim community may note be true elsewhere— and science, too, is less of a sharp-edged body than one might think at first. Even within the Popperian paradigm, while the theory of falsification is clear in principle, when you examine specific instances there are all kinds of diverging views as to whether a given theory has been falsified or not, or whether it is or not falsifiable at all. So, there are more or less central assumptions about what is scientific or not, in communities of scientists which are themselves fuzzy—and other assumptions which are more questionable if only because the evidence is less widely known in the relevant discipline. Broadly speaking, the theory of evolution is of course scientific—but the details of such and such specific theory or specific case may not be as unquestionably scientific. Not everything that Darwin said would pass muster today as solid science, which of course is only to be expected in the process of scientific developments. This doesn’t make his theory the less important for the history of biology.
(Ponen por cierto un link interesante a un artículo de Douglas L. Theobald, "A Formal Test of the Theory of Universal Common Ancestry", un modelo sobre cómo la probabilidad estadística puede servir como criterio de falsación de la teoría de Darwin sobre el origen común de todos los seres vivos).
Me contesta muy airado y despectivo uno de los interlocutores, Federico Calvoli, del Imperial College London—aquí su respuesta y mi instructiva réplica.
#
Federico Calboli · Imperial College London
"I think truth comes in all kinds of fuzzy packets"
This statement is utterly pointless and unhelpful. The word ’truth’, as used in day to day basis is often no more than a statement of opinion than anything else (’what my ridiculous religious tenets say is true’) has nothing to do with the issue of science.
Point one, as Popper pointed out, scientific theories *are not fasle*, they are never ’true’, because they are always open to falsification.
Point two it confuses the process of falsification with the fact people have opinions and biases, neither of which is rooted in empirical evidence. The diverging view about any scientific theory are part and parcel of the falsification process, as long as they are rooted in the empirical falsification of a theory. Fabio might disagree on one of my theories because his data do not support my view, or he can disagree on my analysis of the data or my interpretation of my results. All these disagreements are perfectly fine (and as Popper pointed out, necessary part of science) because they are based on *empirical data*. Data can be tested for soundness and correctness, analysis of data can also be tested for soundness and correctness, and disagreements about interpretation of results can also be resolved by empirically producing and analysing more data. The constant update of scientific theories does not invalidate a Popperian view of science, because it is part of it. The theory of evolution is a perfect example of a theory that is empirically falsifiable and has undergone multiple updates as more empirical evidence has come to the fore, and these properties make it scientific.
If you, on the other hand, disagree with my theory ’because there are different points of view", and fail to address the disagreement *empirically* your opinion is utterly pointless and irrelevant.
José Angel García Landa · Universidad de Zaragoza:
Oh well, don’t let’s be so "utterly". My opinion may be utterly pointless and irrelevant to you, other people may see in it some kind of point. It’s not "pointless and irrelevant" in itself, but "for someone". Your opinion is partly pointless to me, but not wholly so. When I spoke of truth I was not speaking of science, but of all kinds of "truth effects". Science is only one provider of such truth effects. You may disagree there; however perhaps we’re on more common ground if we agree that science is the only provider of scientific truth effects. Still that’s a panoramic statement of the issue, and (I insist) whenever we get down to the details things get fuzzier, once again. Much scientific discussion, for instance, is on a "nowhere land" (or a somewhere land, if you prefer) between empirical backing and falsification. Why? Because not everyone whose views or experiments are potentially relevant to the issue agrees on the interpretation of the data, or even has all the available data. There’s too much going on at once. Your clear-cut view of what counts as scientific presupposes a self-evidencing falsification taking place "in itself", as against "for someone", or a sole context of relevant evaluation, which is an idealistic artifact. Sorry if I’m pointless again.
#
Les Kaufman · Boston University ×
The theory of evolution is science because it is based on evidence, not faith, and generate testables hypotheses.
#
Federico Calboli · Imperial College London ×
Josè, you are charging though a wide open door, when you state that "not everyone whose views or experiments are potentially relevant to the issue agrees on the interpretation of the data, or even has all the available data". Nobody here is saying otherwise, in fact I did say that the differences in opinion on how to generate and interpret the data is integral part of the falsification process, which is normally not a fast and clean cut process.
What is clear cut is that, scientific praxis is not just pontificating and spitting out opinions. It is a debate based on empirical data generated to falsify a prediction arising from a theory. The fact that falsification is not a clear cut process does not make it in any way similar to people debating religion, social norms or the relevance of comic strips in how architectural design evolved through time.
#
Federico Calboli · Imperial College London ×
The difference between science and other stuff:
http://store.xkcd.com/xkcd/#Science
#
José Angel García Landa · Universidad de Zaragoza ×
Lots of things work, besides science - in non-scientific ways, of course. Even falsified science works in the right context (e.g. Newton’s gravity). And, what’s more, every scientific discipline plays data and theories against each other following different protocols. Which is not to say that I completely disagree with what you say, not in the least.
#
Julie Hebert · University of Maryland ×
I think part of the problem, particularly regarding evolution, is the difference between common definitions and biological/scientific definitions. A theory to a layman is an idea, perhaps based on some logic, but not a proven fact. A theory to a biologist is a testable hypothesis that has been found to be true in many cases, and therefore is as close to a law as we tend to get in biology. (The "problem" with biology as a science is that there are no laws - because of the stochasticity of the biological world, there aren’t broad predictions we can make for something to happen everywhere and always, at least not unless we reduce the circumstances to something so specific that it doesn’t make sense for it to exist as a "law".)
As for evolution, many of the common definitions you can find on the web or in dictionaries include "gradual change" and from "a simple to a complex form" however those do not necessarily apply to a biological definition. In its most basic definition, evolution is change through time, or changes in allele frequencies (or phenotypic frequencies) in populations from generation to generation. Using that definition, it is hard for someone to show that evolution does NOT occur. The underlying mechanisms may differ in different cases (gradual vs. rapid, drift vs. natural selection, etc.) but evolution itself allows for all of those mechanisms to exist, and they are not necessarily mutually exclusive. So, in terms of science, I think it evolution is actually one of the more straight-forward and easily testable scientific concepts.
José Angel García Landa · Universidad de Zaragoza ×
I’m not one to disagree, Julie. A phenomenon such as genetic drift can be tested in laboratory conditions and, using statistical models, in actual populations as well. But as Stephen Jay Gould liked to say, biology is also a historical science. When it comes to case studies, the variables become too many to handle, too many disciplines have to cooperate to suggest and interpretation, and the fuzziness I mention reappears. Take a spectacular case, dinosaur extinction. Part of the evidence to be used in a theory accounting for it will be testable in terms of "hard science", take e.g. experimental ways of determining the levels of iridium in a layer of rock—but there are just too many sides to the question in the final account, and partial rock-solid evidence added to probabilistic interpretations results in a whole panoply of different kinds of evidence. And if the result is science, it is also a kind of narrative resulting from many different kinds of science, none of which alone would be able to give a scientific account of the fact under study, i.e. the disappearance of dinosaurs. Lots of things are testable on the way, but the global account as such is not testable.
Fabio Machado · Universidade de São Paulo ×
Jerry Coyne started a similar discussion at his blog. Maybe something in his comment section could be of some use.
http://whyevolutionistrue.wordpress.com/2012/04/29/is-falsifiability-a-good-criterion-for-a-scientific-theory/
I think that José’s "unfalsifiable" historical narrative fits the idea of best-explanation inference, but others could argue that, since this narrative have some logical testable implications, the narrative itself is testable.